America's "transgender moment" has dramatically increased awareness of the struggles faced by the roughly 0.6 percent of Americans who are transgender. If such awareness ends up inspiring sympathy and respect, as well as greater legal protections, for this vulnerable population, it will be a very good thing.

What is much less good, and indeed downright pernicious, is the way that transgender activists have lately begun going about trying to achieve these worthwhile aims. They make extremely radical claims about the character of transgenderism and then browbeat critics into accepting the dubious truth of these assertions by insisting that the rejection of them amounts to transphobia, trans bashing, and other gratuitous moral offenses. This approach runs a very real risk of sparking a dangerous backlash against transgender people. And if it does, that backlash will be all the more damaging because it will be at least partially justified.

Consider an illuminating contrast highlighted in Ryan T. Anderson's informative, provocative, but also obnoxiously titled and sometimes rhetorically reckless new book When Harry Became Sally: Responding to the Transgender Moment. In 2005, the advocacy and lobbying group Human Rights Campaign described the gender dysphoria that accompanies the desire to transition medically from one gender to another as a person's "discomfort from the strong internal sense that their true gender identity does not match their physical sex."

A transgender person … is someone whose sex assigned at birth is different from who they know they are on the inside … Gender Identity is one's internal concept of self as male, female, a blend of both, or neither. It is how individuals perceive themselves, and what they call themselves. One's gender identity can be the same or different from their sex assigned at birth. For transgender people, their birth-assigned sex and their own sense of gender identity do not match.

The earlier view presumes the existence of something given or natural (physical sex) and something else that's rooted in subjectivity and social convention (perception of gender), and then holds that the two can be misaligned. A child born a boy can feel himself to be a girl. If this perception persists into adolescence and then adulthood, modern medicine can deploy hormone treatments and surgery to bring the boy's body more closely into alignment with that perception. The boy's given (natural) condition can be altered to approximate his subjective experience of himself as a girl.

The more recent view breaks in a radical way from the earlier understanding of things by inverting the relationship between the given or natural and the conventional. Now sex is held to be arbitrarily "assigned at birth" and can be freely manipulated by the self, which has an essential gender (be it male, female, some mix of the two, or even something else entirely). No matter what sex was assigned to a person at birth, that person can claim to be, in essence, another sex, and this claim must be unwaveringly accepted and affirmed by everyone. A person with breasts, a uterus, ovaries, and vagina can call herself a man, and the rest of us are obliged to recognize and socially validate the truth of this assertion, very much including at the level of the pronoun.

There's just one problem: The assertion isn't true.

Sex isn't "assigned" at birth. It's determined before birth by genetics, which makes some babies girls and other babies boys. This difference is recognized and responded to by mothers and fathers and society at large in a multitude of different ways across a multitude of different cultures, generating a slew of norms or conventions around gender — all of them making sense and meaning of the fact that boys and girls, and then men and women, are different by nature in certain significant ways, with the most significant difference of all being the fact that women can become pregnant and give birth to children while men impregnate them, and that both capacities are a function of distinct sets of organs and a distinct mixture of hormones.

The self that current transgender ideology insists has an essential gender and whose feelings and desires must invariably be deferred to, including when they override the reality of physical sex, is in nearly all cases shaped and mediated by its embodied experience as either male or female. (The roughly 0.05 percent of babies born intersex, or with genitalia ambiguous enough to make it difficult or impossible to describe them as either male or female, are the rare exception.) Even when this body is altered by hormones and surgery, the starting point, what is being altered or transformed by medical intervention, is the sex that the transgender person always already was at birth, prior to any social or cultural assignation at all.

A human being is not a disembodied self sitting behind a control panel in the mind, possessing some indubitable intuition about its true sex (which, incidentally, always just so happens to draw on culturally specific images and ideals of embodied masculinity and femininity). We are our bodies, and these bodies are (aside from those rare intersexual exceptions) male or female.

This bodily reality can no more be denied than we can deny our own mortality.

Anderson is very good at analyzing the intellectual folly of this recent radical shift in thinking about what it means to be transgender. He's even better at showing how this thinking can encourage drastic acts of medical intervention to facilitate a hasty and ill-considered transition that the person who undergoes the procedure comes to regret, requiring "detransition." When this happens in the case of minor children, who in the vast majority of cases would outgrow their gender dysphoria without any hormonal or surgical intervention at all, the consequences are both alarming and infuriating.

Anderson is less helpful in his insistence on exclusively highlighting cases of unhappy transitions, as if no one had ever felt relief and a greater sense of personal wholeness and happiness from undergoing a sex change. The same overabundance of skepticism leads Anderson to adopt the rhetoric of pathology to describe gender dysphoria and transgender people, who are said to be in the grip of thoughts and feelings that are "utterly disconnected from reality, persistently false and unfounded," and even outright "delusional."

That's going too far. The contemporary ideology of transgenderism may encourage delusional thinking about the reality of given sex differences, but gender dysphoria itself is clearly a real and persistent human experience that's been present across a range of cultures down through the ages. What's distinctive about our own time is that modern medical science gives those who are prone to such experiences the option of transforming their bodies to bring them into closer conformity with their perception of their own gender. This makes gender transitioning continuous with other modern medical trends that involve the manipulation of bodies to serve human ends and desires, such as contraception, plastic surgery, artificial insemination, and gene editing.

The reason why Anderson is incapable of giving such efforts their due is that he's implicitly committed to an older notion of human flourishing — one rooted in the Roman Catholic Church's teachings about sexual morality — that looks down on these and many other modern trends. How else to explain his otherwise inexplicable decision to blame the most radical and dubious aspects of transgender ideology on the rise of modern feminism? The connection between the two will be clear only to those who share Anderson's eminently questionable socially conservative premises and assumptions.

But that doesn't take away from the value of Anderson's book. At a moment when transgender activists are telling us that moral decency requires us to affirm things that simply aren't true, Anderson is brave enough to call them out and remind us that this is a price far higher than any of us — transgender or not — should be willing to pay.